1. Field of the Invention
The present invention relates to a switch device in which an operating member movably retained at the upper portion of a case is operated in order to selectively operate a plurality of switch elements in the case.
2. Description of the Related Art
An example of such a switch device in which an operating member is operated to selectively operate a plurality of switch elements is the mirror switch device which is used, for example, to remotely operate the left and right mirrors provided on the body of an automobile, and the mirror angle from an operator's seat by making use of the driving power of a motor.
A description of such a conventional mirror switch device will be given, with reference to FIGS. 5 to 7. FIG. 5 is a vertical section of the conventional mirror switch device, FIG. 6 is an exploded perspective view thereof, and FIG. 7 is a bottom view of the case of the conventional mirror switch device.
Referring the figures, reference numeral 20 denotes a case with an open bottom, which has a partition wall 21 provided therein. Above the partition wall 21 are provided side by side a relatively deep hollow section 22 which is substantially square-shaped in a plane and is relatively deep, and a shallow recess 23 which is substantially rectangular in a plane. Cylindrical, annular walls 24 are formed upright at four corners of the hollow section 22 so as to project below the partition wall 21. Through holes 25 are formed so as to extend in the vertical dimension. A projecting wall 27 defining a through hole 26 which is cross-shaped in a plane is formed at about the central portion of the hollow section 22. The upper end thereof is slightly higher than the annular walls 24. A drainage hole 28 is formed at one side of the case 20, with which the hollow section 22 communicates with the open bottom of the case 20. A slot 29 is formed in the recess 23, and a pair of guide plates 30 extends vertically and parallel to each other at the back side of the recess 23 via the slot 29. An operation member 31, being substantially square-shaped in a plane, is retained in the hollow section 22 such that it can be moved vertically. More specifically, the member 31 is retained by retaining pawls 32 that are retained by the peripheral sides of the through hole 26 formed in the hollow section 24. The retaining pawls 32 are disposed so as to extend vertically from four locations at the lower central portion of the operation member 31. It is to be noted that the operation member 31 is inserted in the hollow section 22, with a click rubber 33 provided between it and each annular wall 24.
Reference numeral 34 denotes a cover for covering the lower open end of the case 20, and is snapped in the case 20 in order to form the outer shell of the switch device. A guide wall 35 is formed in the cover 34 so as to extend vertically. It defines three first accommodating sections 36 rectangular in a plane, and one second accommodating section 37 rectangular in a plane. Drainage holes 38 are formed so as to extend vertically through a peripheral section of the cover 34, and communicate with the drainage hole 28, when the cover 34 is mounted to the case 20. A plurality of small holes 29 are formed in the cover 34. First slides 40 are disposed such than they can reciprocate in their respective first accommodating sections 36, while a second slider 41 is disposed such that it can reciprocate in a second accommodating section 37. A tapered face 40a forms an end of each first slider 40, while a spring receiving section 40b forms another end thereof, with a spring 42 interposed between each spring receiving section 40b and a guide wall 35. A recess 40c is formed in the upper portion of each first slider 40, with a first sliding member 43 serving as a movable contact inserted and retained in each recess 40c. On the other hand, a drive projection 41a is formed on the upper surface of the second slider 41, with a pair of recess sections 41b formed on each side of the drive projection 41a. Second sliding members 44 serving as movable contacts are inserted and retained in the recess sections 44b.
Reference numeral 45 denotes a printed board which is interposed and fixed between the case 20 and the cover 34, and keeps the first sliders 40 and the second slider 41 in the first accommodating sections 36 and the second accommodating section 37, respectively. In addition, the printed board 45 has formed therein a pair of cutouts 45a, circular holes 45b, and a rectangular hole 45c, with the tapered face 40a of each first slider 40 facing the cutouts 45a, 45a, and the hole 45b, respectively, and the drive projection 41a of the second slider 41 inserted in the hole 45c so as to project upwardly of the printed board 45. A connector 46 is soldered and an illuminating lamp 47 is mounted onto the upper surface of the printed board 45, while a plurality of sets of fixed points (not shown) form patterns on the lower surface of the printed board in correspondence with the sliding members 43 and 44. The lamp 47 and the fixed point layout patterns are connected to a connector 46, with a connector pin 46a of the connector 46 passing through the small hole and out the cover 34.
Reference numeral 48 denotes drive rods, each of which has an upper small diameter section 48a and a lower large diameter section 48b, with both ends of the small diameter section 48a and those of the large diameter section 48b formed into a spherical shape. The small diameter sections 48a of the drive rods 48 are fitted into three of the through holes 25 so as to be movable in the vertical dimension, with the upper end of each small diameter section 48a contacting the lower face of the operation member 27, and the lower ends of the large diameter sections 48b passing through the cutouts 45a and the holes 45b in the printed board 45 so as to contact the tapered faces 40a of the first sliders 40.
A drive member 49 is disposed between the guide plates 30. A joining section 49a projects out from the upper central portion of the drive member 49, and is joined to a slide knob 50 disposed on the recess 23 by being snapped in the slot 29, whereby moving the slide knob 50 along the slot 29 from above the case 20 in a reciprocative fashion causes the drive member 49 to reciprocate along the guide plate 30 in the same dimension as the reciprocative movement of the slide knob 50. A thick-walled section 49b is formed on each end of the drive member 49, with the thick-walled sections 49b having from therein a first blind hole 54 and a second blind hole 52, respectively, extending from a side thereof. A ball 58 is accommodated in either one of the first blind hole 51 and second blind hole 52 via a spring 57. A pair of retaining walls 49c are formed so as to extend vertically at the lower central surface of the drive member 49, between which the drive projection 41a of the second slider 41 is positioned. As shown in FIG. 6, four cam sections 53, 54, 55, and 56 are formed at four locations at the inner side of the guide plates 30. The ball is such as to be either in engagement of out of engagement with any one of the cam sections 53, 54, 55, and 56, so that the drive member 49 clicks during operation. Four different click operations can be felt by the operator using common component parts as a result of selecting either the first blind hole 51 or the second blind hole 52 as the accommodating member of the spring 57 and the ball 58, and selecting the direction of insertion of the guide member 49 between the guide plates, with the directions of insertion being opposite each other or differing by 180 degrees. The case 20 and the cover 34 are firmly secured to the printed board 45 with a setscrew 59.
A description will now be given of the operation of the switch device with the above-described construction. When the slide knob 50 which projects above the case 20 is at an intermediate position, the motor is not driven, regardless of whether or not the slide knob 31 is pressed for driving a mirror. When the slide knob 50 is moved from its intermediate position along the slot 29, and reciprocates between both guide plates 30, the retaining walls 49c of the drive member 49 move, causing the second slider 41 to reciprocate in the second accommodating section 37, and thus causing the second sliding members 44 held by the second slider 41 to slide on the fixed contact patterns (not shown) on the bottom surface of the printed board 45 so that they are positioned relative to each other. This switches the contact point of the selection circuit, causing either the left or right mirror to be in a driving waiting state. In this case, the ball 58, accommodated in either the blind hole 51 or 52 of the drive member 49, repeatedly engages with and disengages from either one of the first to fourth cam sections 53 to 56 formed in the guide plates 30, while being subjected to resilient force exerted by the spring 57, so that the operator can recognize whether or not the slide knob is at the intermediate position, or the left and right switching state by a predetermined click felt by the operator.
When a certain location of the slide knob 31 is pressed, the drive rod 48 located below the pressed location of the knob 31 moves downward in relation to the respective through hole 25 below. The movement of the drive rod 48 becomes horizontal at the tapered face 40a of the first slider 40 below, which moves in opposition to the spring 42 into the first accommodating section 36. Movement of the first slider 40 causes the first sliding member 43 held by the above slider 40 to slide on the fixed point patterns (not shown) formed on the lower surface of the printed board 45, whereby the switch in correspondence with the pressed location (pressed member) of the operation member 31 is selected from the three slide switches, and turned on. In response to the ON signal, the motor (not shown) rotates in either the forward or reverse direction, producing a driving power which is transmitted through a power transmission system (not shown) to the mirror selected first, as a result of which the mirror is driven. In this case, when the operation member is pressed, the click rubber 33 below the pressed location is deformed, making it possible for the operator to know whether the switch has been turned on based on a predetermined click felt by the operator. When the predetermined location of the operation member 31 is released, the operation member 31 is restored back to its original state by the restoring force of the click rubber 33, while the first slider 40 and the drive rod 48 in contact with the first slider 40 are restored back to their original state by the restoring force of the spring 42, as illustrated in FIG. 4, as a result of which the switch is turned off.
In the switch device having the above-described construction, however, when the operation member 31 or the knob 50 is operated, the first sliding member 43 retained by the first sliders 40 or the second sliding member 44 retained by the second slider 41 slides on the lower surface of the printed board 45, causing the contact point section is to be worn after long use, which may prevent switching operations as a result of contact failure. In addition, the first sliding member 43 is disposed in the recess 40c of the first slider 40, while the second sliding member is disposed in the recess 44b of the second slider 41, thus resulting in a complicated contact section structure, so that experience and time are required for assembling the structure.